rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10608/1:b..l P13843/1:b..l P5875/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=75989, q=380 ncpus=2)
task:syz-executor state:R running task stack:21568 pid:5875 tgid:5875 ppid:5855 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:debug_lockdep_rcu_enabled+0x2d/0x40 kernel/rcu/update.c:320
Code: fa 31 c0 83 3d 57 58 29 04 00 74 1e 83 3d 6a 88 29 04 00 74 15 65 48 8b 0c 25 08 d0 a0 92 31 c0 83 b9 ec 0a 00 00 00 0f 94 c0 f9 f1 95 f5 cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90
RSP: 0018:ffffc90003fe7150 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffffffff81fb0589 RCX: ffff888032a68000
RDX: 0000000000000001 RSI: ffffffff8dba98b5 RDI: ffffffff8be33f00
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff8172c195
R10: dffffc0000000000 R11: ffffffff81ac3b00 R12: 1ffff920007fce45
R13: ffffc90003fe7260 R14: ffffc90003fe7228 R15: ffffffff8172c195
rcu_read_lock include/linux/rcupdate.h:842 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xcb/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
free_unref_folios+0xdbd/0x1520 mm/page_alloc.c:2952
folios_put_refs+0x559/0x640 mm/swap.c:999
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1157
shmem_truncate_range mm/shmem.c:1269 [inline]
shmem_evict_inode+0x272/0xa70 mm/shmem.c:1397
evict+0x504/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:669
dput+0x19f/0x2b0 fs/dcache.c:911
__fput+0x68e/0xa70 fs/file_table.c:476
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6c4b58d88a
RSP: 002b:00007ffec80e5610 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f6c4b58d88a
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007ffec80e566c R08: 0000000000000000 R09: 00007ffec80e5377
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000016f
R13: 00000000000927c0 R14: 00000000000e2d26 R15: 00007ffec80e56c0
task:udevd state:R running task stack:24648 pid:13843 tgid:13843 ppid:5228 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 7b 71 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000459f6d8 EFLAGS: 00000206
RAX: d149f070030f8100 RBX: 0000000000000000 RCX: d149f070030f8100
RDX: 0000000000000000 RSI: ffffffff8dba98b5 RDI: ffffffff8be33f00
RBP: ffffffff8172c195 R08: 0000000000000000 R09: ffffffff8172c195
R10: dffffc0000000000 R11: ffffffff81ac3b00 R12: 0000000000000002
R13: ffffffff8e13a0e0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:330 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:356
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4191 [inline]
slab_alloc_node mm/slub.c:4240 [inline]
kmem_cache_alloc_lru_noprof+0x1c6/0x3d0 mm/slub.c:4259
shmem_alloc_inode+0x28/0x40 mm/shmem.c:5211
alloc_inode+0x6a/0x1b0 fs/inode.c:346
new_inode+0x22/0x170 fs/inode.c:1145
__shmem_get_inode mm/shmem.c:3110 [inline]
shmem_get_inode+0x346/0xe90 mm/shmem.c:3184
shmem_symlink+0xa3/0x510 mm/shmem.c:4158
vfs_symlink+0x143/0x2f0 fs/namei.c:4730
do_symlinkat+0x1b1/0x3f0 fs/namei.c:4756
__do_sys_symlink fs/namei.c:4777 [inline]
__se_sys_symlink fs/namei.c:4775 [inline]
__x64_sys_symlink+0x7a/0x90 fs/namei.c:4775
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9b3ab15527
RSP: 002b:00007ffd1a2c60f8 EFLAGS: 00000206 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 000055a4e0ccf7d0 RCX: 00007f9b3ab15527
RDX: fffffffffffffe68 RSI: 00007ffd1a2c6100 RDI: 000055a4e0cbe1e0
RBP: 0000000000000ee9 R08: 0000000000000064 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffd1a2c6100
R13: 000055a4e0cbc190 R14: 0000000000000008 R15: 000055a4e0ccf7d0
task:syz-executor state:R running task stack:18856 pid:10608 tgid:10608 ppid:10590 task_flags:0x20400140 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7145
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7169
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
_raw_spin_unlock_irq+0x45/0x50 kernel/locking/spinlock.c:202
spin_unlock_irq include/linux/spinlock.h:401 [inline]
loop_queue_work drivers/block/loop.c:863 [inline]
loop_queue_rq+0x9f8/0xb00 drivers/block/loop.c:1887
__blk_mq_issue_directly block/blk-mq.c:2695 [inline]
blk_mq_request_issue_directly+0x3c1/0x710 block/blk-mq.c:2782
blk_mq_issue_direct+0x2a0/0x660 block/blk-mq.c:2803
blk_mq_dispatch_queue_requests+0x6fe/0x800 block/blk-mq.c:2878
blk_mq_flush_plug_list+0x432/0x550 block/blk-mq.c:2961
__blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
blk_finish_plug+0x5e/0x90 block/blk-core.c:1247
btrfs_write_and_wait_transaction fs/btrfs/transaction.c:1265 [inline]
btrfs_commit_transaction+0x1d24/0x3950 fs/btrfs/transaction.c:2536
sync_filesystem+0x1cf/0x230 fs/sync.c:66
generic_shutdown_super+0x6f/0x2c0 fs/super.c:622
kill_anon_super+0x3b/0x70 fs/super.c:1282
btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2120
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f07b318ff57
RSP: 002b:00007ffe6d866d28 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f07b3211c2d RCX: 00007f07b318ff57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe6d866de0
RBP: 00007ffe6d866de0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe6d867e70
R13: 00007f07b3211c2d R14: 00000000000e28cb R15: 00007ffe6d867eb0
rcu: rcu_preempt kthread starved for 10438 jiffies! g75989 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:R running task stack:26792 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 3e fd 95 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d b3 e9 0d 00 f3 0f 1e fa fb f4 13 fd 95 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c2
RAX: 641fc9949572fb00 RBX: ffffffff819683f8 RCX: 641fc9949572fb00
RDX: 0000000000000001 RSI: ffffffff8d9ba295 RDI: ffffffff8be33f00
RBP: ffffc90000197f20 R08: ffff8880b8732f9b R09: 1ffff110170e65f3
R10: dffffc0000000000 R11: ffffed10170e65f4 R12: ffffffff8fa3a630
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110039d9b40
FS: 0000000000000000(0000) GS:ffff888125d13000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31817ff8 CR3: 0000000076d4b000 CR4: 0000000000350ef0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147